Method of refining petroleum



' P. AT. SHARPLES. METHOD 0F REFINING PETROLEUM. APPLICATION FILED MAR. 12| 1920.

Patented May 23, T9223..

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NETE@ STATES' PTNT @FFECEO PHILIP T. SHARPLES, OF vS'J?. DAVIDS, PENNSYLVANIA. 'l

METHOD or REFINING PETROLEUM.

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To all 'whom t may concern.'

Be it known that l, PHILIP T. SHARPLES, a citizen of the United States, residing at St. Davids, in the county of Delaware and State of Pennsylvania, have invented a certain new and useful Method of Refining Petroleum, of which the following is a specification.

This 'invention is a petroleum refining method designed primarily to improve the product and increase the yield of lubricating oils, as also toreduce the time, simplify the installation for and reduce the cost of ,relining.

In the usual present commercial method, the crude oil (from which foreignmatters such as water, dirt and 13. S. have been removed) is steam distilled by the application of fire and steam-to the oil contained in the still. The products distilll off in the order of their boiling points, in sequence as gas, naphtha, burning oils, light lubricating distillate and heavy lubricating distillate, these being separately condensed and collected and leaving a residue in the still known as cylinder stock. The light lubrieating distillate thus obtained contains paraffin wax, which wax is removed therefrom by chilling and filter pressing. The heavy lubricating distillate, on the other hand, contains wax .which cannot be removed by filter pressing, for the wax is in such a condition that it rapidly clogs up the filter medium. vSuch heavy oils must therefore be redistilled or cracked The wax is thus changed to the crystalline state and is removed by filter pressing. This redistillation of the heavy lubricating distillate is objectionable because a large part of the oil is broken down into naphtha, burning oils, and coke, and the remainder is much lower in viscosity than in its former condition.v

ThisA loss of oil and change in viscosity is an unavoidable consequence of bringing the wax toa condition in which .it can be removed by filter pressing.

The light lubricating distillate and the product, cracked distillate, obtained by redistilling the heavy lubricating distillate are very much the same and are frequently combined and filter pressed together. lin filter pressing the crystalline paraffin, wax remains in the filter press, the wax free oils passing therethrough. The wax free oils must then be redistilled to produce the va- 'rious viscosities which are required for lu- Specication of Letters Patent.

Application led March 12, 1920. Serial No. 365,135. y I

b rication. ln this distillation, the spindle oils. (the very light lubricating oils) are distilled off, distillation 'continuing until the residue has the required viscosity. This relsidue is commonly referred to as neutral o1 f The residue in the still from the first distillation of crude is gravity settled to remove the wax by dilution with naphtha, chilling, settling, drawing off the clear supernatant liquid and reducing, producing bright cylinder stock. The bright cylinder stock and the neutral oils are then blended to produce various market products of intermediate viscosities.

By the method of my invention, the lubrieating residue in the still, after the removal of gas, naphtha and burning oils by distillation and before the distillation of the light lubricating oils, is diluted with naphtha, chilled and passed through a centrifugal separatorlfrom which the wax free diluted lubricating residue is discharged on the one hand and the wax on the other. The bright lubricating residue is vthen steam distilled by which there are obtained in succession the naphtha used in dilution, the spindle oil and the finished product of lubricating oil which remains as a residue in the still, the distillation being continued until this residuoI has the viscosity and fire test required in the finished product. c

This improved method not only eliminates thc cru-cking distillation of the heavy lubri rating oils together with further recited operations of the former method, but it greatly increases the yield of finished lubricating oilsy it avoids all of the several overhead distillations of the former method and resulting deterioration of valuable lubricatiing,` products` b v the high temperatures necessary for drivingr the lubricating oils overhcaih and it further avoids the necessity in the former method of installing two complete and separate outts for the removal of the wax. namely. an outfit comprising a. filler press for the separation of crystalline wax and another comprising the gravityA settling means for the removal of amorphous wax from cylinder stock.

Y The accompanying drawing is a compara-* tive diagrammatic illustration ofthe characteristic .operations of my improved method together with the old method, the eliminated operations of the known method being indicated by broken lines.

lill@ As illustrated, in accordancevivith both the old and the new method, the crude oils (free of foreign matters). are'heated in the' of these constituents.

loff thrbugh the conduit 11 to .the

In accordance with the method usually practiced heretofore, 1the distillation is con-- tinued so :as to carryI overhead the light lubricating distillate. which passes oif through the` conduits 2, 6 and '7 to a press 8; thereafter the heavy lubricating distillate, which passes off. through the conduits 2 and-9 to a still 10, where cracking distillation is effected, andicylinder stock is carried ravity settling tank 12. Naphthapasses o from the still l0tliroughthe conduit 13 and the condenser 13e, and thereafter light .lubricat-A ing distillate, which flows through the con duits 13, condenser 13A, 14 and 7 to the press 8, leaving a residue of coke as indicated by the conduit 15.. The press 8 delivers wax free oil. which loivsfthroughthe :conduit 16 to `theistill 17 and paraffin, which is delivered throughthe conduit-s 16 and 18. .The

still 1T delivers iii succession.'V through the conduit 20, spindle oil vas -iiidicatedby the branch conduit 21 and neutral-lubricating cil as indicated by the conduit 23. The lubricating 4oilflowing .through the. conduit 23fis .blended -With the gravity separated bright .cylinder stock drawn off .fromi the tank 12 through the -conduit 24', the sepa rated petrolatum lin the tank. being .indicated bythe conduit 25,-..

In accordancewiththe methdd-of inyin vention, a after the gas, .iiaphtha and burning oils have been passed off -frointhe still 1 through the conduit 2, the lubricating residueis drawn-f oifl fromfthe still through the conduitl 26, this residue .being diluted with naphtha'and chilled to precipitate-the amorphous -wa-X. The chilled oil .is passed from'the conduit 26.through. the centrifugal ,separator-28' which .separates'the wax from the -brightlubricatingresidue.v The Wairis delivered -from-Itheiseparator, as indicated-by the conduit `29, and the bright lubricating 'residue is discharged through a conduit- 30'to the' still 31,- which delivers in succession, the naphtha -used in d ilutionand spindle -oil through. the conduit 32, 'and the finished I I residual .llubricatingi product through the :conduit |34.--

A5 :a definite-:illustration of the practice..

of my inventionfthefollowingfexample is 4given# f Pennsylvania .-crude 'petroleinn was dis-4 tilled'r-withf irei-and-.steam \to remove the.

gas,Y -naphtliai and other i light` "ingredients, untilthedistillatecomingof'shewed a s eff cific gravity oerrespendingto R41-13e.y This of very fine Waxparticles-which might tend -to be held in colloidal suspension'and to secure uniformity. of distribution of the Wax in order to reduce the necessity for chang-V ing ythe adjustment ofthe centrifugal -machine. After the stock was thus properly chilled, it was in this instance treated in a centrifugal vmachine operated in accordancewith my Patent 1,232,104, from which foil and Wax Were continuously and separately dischargedf. The..oil and -wax were then separately distilled to removeI the' iiaphtha,`

andthe eil which resulted Wasa heavy lubricating; oil having the physical properties of 'a finishedproduct;

.The method of treating a petroleum `.residue obtained by distilling off gas, naphthaand burning oils from crude petroleum without cracking the residue substantially,- Which consists .in chilling the residue 'ob-1 tained thereby with precipitation of the Wax therein; subjecting the chilled residue to centrifugal .treatment adaptedforseparating Wax from 'the"residue.l and` separately 'clis- Havingdescribed my invention, I claim charging theseparated Wax and the-Wax v freed residue continuously.

'2. `The method of treating residue ob-rtained by distilling oli the gas; naphtha and burning oils from crude petroleum Without crackingthe residue substantially, A which consists -in diluting the residue; chilling the diluted4 residue 'with precipitation of wax therein; subjectingthe chilledl diluted residue to centrifugal treatment adapted to'separate Wax therefrom and separately 'dis-g charging the wax-and the wax=freed product continuously; distilling off the diluent, and-c -distilling the WaX.freed residue.

3. The method of refining residue obtained. 'by' distillingv crude .petroleum without cracking kSaid-residue substantially, which consists in-chillingsaid.residue with precipitation of. -Wax therein; centrifu-- the lubricating f gally l separating precipitated' wax from the chilled. residue Withdotation thereoflon an.l inimiscible acarrierA liquid, and steaijiri. 'distil-r ling the separated bright. lubricating 'resiw' due.V

4. The method of'i'eningcrude petroleum rvhich consists in distilflingotfthe. more'vola., tlle lconstituents until'. a residue is .obtainedl which Will'have (after the removal of the Wa-X therefrom) the physical properties required in a iinished lubricating product, diluting said residue, chilling the diluted productwith precipitation of Wax therein,

. subjecting the chilled product to centrifugal treatmentA adapted to separate Wax therefrom and separately discharging thel wax freed product, and distilling off the diluent from said wax freed product with the production of the desired lubricating product.

5. The method of treating a petroleum product containing Wax, which comprises in diluting and chilling the same with the precipitation of the Wax (without crystallization thereof), subjecting the chilled diluted product to centrifugal treatment adapted to separate the wax therefrom, and separately discharging the separated Wax and the Wax freed product continuously.

6. The method of refining the residue of crude petroleum obtained by distilling ofi' the lighter constituents Without substantlally cracking the residue, 'which consists in chilling said residue with precipitation of Wax therein; centrifugally separating Wax from the chilled residue with flotation thereof on brine; and distilling the centrifugally separated bright lubricating residue to drive off the lighter from the residual heavier lubricating oils.

In testimony whereof I have hereunto set my name this 8th day of March, 1920.

P. T. SHARPLES. 

